Feed system for closed reaction chambers with moveable sample racks

ABSTRACT

The invention relates to a system that feeds gaseous or liquid media into moveable sample vessels or reaction vessels in vacuum centrifuges or reaction chambers that are provided with an integrated shaker. An adapter plate fitted with needles that are allocated to individual vessels is arranged inside the centrifuge or reaction chamber above the sample vessels. The adapter plate is provided with a system for the introduction of the gaseous or liquid medium. The height of the adapter plate can be adjusted. This enables the depth at which the needles are introduced into the sample vessels to be chosen at will.

BACKGROUND OF THE INVENTION

The invention relates to a system that feeds gaseous or liquid mediainto a number of moveable sample vessels or reaction vessels on a rotorin vacuum centrifuges or on an integrated shaker plate in reactionchambers, for simultaneous processing of the samples contained therein,with an adapter plate of adjustable height being arranged inside thecentrifuge or reaction chamber above the sample vessels or reactionvessels, with needles that are allocated to the individual samplevessels or reaction vessels being arranged on said adapter plate, andwith a system for the introduction of gaseous or liquid media.

The processing of samples in vacuum centrifuges and reaction chamberscreates problems which have not yet been solved satisfactorily.

The samples are usually in test tubes or racks with appropriaterecesses. As these sample vessels are very narrow, i.e. the ratio ofvessel depth to vessel diameter is very large, the following problemarises: the cooling of the sample due to evaporation makes the neck ofthe sample vessel cold and thereby substantially prevents vapour phasefrom being sucked out of the sample vessels.

A device in which the sample vessels are placed in preheated or heatedracks is known from PCT/CH 97/00431 and vacuum centrifuges. As thecooling due to the energy of vaporization can only be very poorlycompensated by heating or IR radiation, and the sample vessels areusually made of a well insulated material such as glass or plastic, ithas to be accepted that certain applications will involve extremelytedious processes.

EP-A-0 210 014 describes a sample treatment system equipped with adevice for washing the sample vessels. The washing device has needleswhich are arranged in a washing block and allocated to individual samplevessels. The washing block is part of a multi-functional and so-calledintegrated transfer head. The washing block can be moved vertically inorder to introduce the needles into the sample vessels. However, thissystem would be unsuitable for use together with sample vessels thatmove sideways during processing because the washing block is incapableof lateral movement.

WO 90 02605 A describes an apparatus for peptide synthesis which has aliquid feed system, for example for washing the reaction chambers. Theliquid feed system can be moved away from the reaction chambers when itis not needed. Again, this liquid feed system is unsuitable for use withsample vessels that move sideways because it is incapable of lateralmovement.

SUMMARY OF THE INVENTION

The object of the invention is to provide a system which overcomes saiddisadvantages of the state of the art.

According to the invention, this object is achieved by a feed system ofthe type mentioned at the outset, which is characterized in that theadapter plate is rigidly connected to the rotor or the shaker plate inits direction of motion in such a way that the needles can be introducedinto the sample vessels while the rotor or the shaker plate is moving.

This system makes it possible to introduce warm gas or liquid into themoveable sample vessels in order to prevent the neck of the samplevessel from becoming cold during the evaporation process and to enablereagents to be introduced simultaneously into the individual samplevessels.

The adapter plate and the sample rack, or the rotor in the case of acentrifuge, are coupled together so that the position of the needle inthe corresponding sample vessel remains unchanged during shaking orcentrifugation. Preferably, the adapter plate can be heated so that themedium is preheated when it flows into the sample vessels. In the caseof systems used in vacuum evaporators, the flow rate of the preferablyinert gas is reduced so as at least to prevent the neck of the samplevessel from becoming cold. The faster the gas flow, the more powerfulthe vacuum system has to be in order to maintain the desired vacuum inthe reaction chamber.

Operating this device under pressure demands an appropriatepressure-resistant reaction chamber designed according to the state ofthe art as described in PCT/CH 97/00431.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a preferred embodiment of the invention.

DESCRIPTION OF THE PRESENT INVENTION

A preferred embodiment is illustrated in the following description withthe help of the attached drawing:

As shown in the drawing, a reaction chamber 1 is closed at the top by aglass plate 2. The reaction chamber accommodates a shaker plate 3 onwhich a sample rack 4 with sample vessels 5 is placed. An adapter plate6 with needles 7 is located above the sample rack 4 and is fixed toguide pegs 8 firmly connected to the shaker plate. The adapter plate 6thus moves synchronously with the shaker plate 3 and the sample rack 4.Via a gas introduction system 9 and a flexible transfer line 13, gasflows through a heat exchanger 12 into the adapter plate 6, which can beheated by means of infrared lamps 10 arranged above the glass plateoutside the reaction chamber. The gas flows through the adapter plate 6,warms up and flows through the needles 7 into the sample vessels 5. Thegas or vapours are sucked out of the reaction chamber 1 via the vacuumpump system 11.

Suitable needles are glass, metal or plastic capillaries or, in the caseof centrifuges with outward-swinging sample vessels, flexible fusedsilica, Teflon or plastic capillaries.

In vacuum centrifuges in which the adapter plate and the capillariesrotate together with the sample vessels, the gas introduction system isconnected at the centre of the adapter plate by means of sealing systemsknown per se.

The gas introduction system, the vacuum pump system and the reactionchamber with heat radiators are known per se in the relevant state ofthe art and do not therefore need to be described in greater detailhere.

Of course, by adapting the apparatus accordingly, gas can also beintroduced under pressure. The reaction chamber and gas introductionsystem are designed for the required pressure range according to theappropriate state of the art.

What is claimed is:
 1. System that feeds gaseous or liquid media into anumber of movable sample vessels or reaction vessels on a rotor invacuum centrifuges or on an integrated shaker plate in reactionchambers, for simultaneous processing of the samples contained therein,with an adapted plate of adjustable height being arranged inside thecentrifuge or reaction chamber above the sample vessels or reactionvessels, with needles that are allocated to the individual samplevessels or reaction vessels being arranged on said adapter plate, andwith a system for the introduction of gaseous or liquid media, whereinthe adapter plate is rigidly connected to the rotor or the shaker platein its direction of motion in such a way that the needles can beintroduced into the sample vessels while the rotor or the shaker plateis moving.
 2. Feed system according to claim 1, wherein a vacuum pump isconnected to the centrifuge or reaction chamber and maintains a vacuumin the centrifuge or reaction chamber during the introduction of gaseousmedium.
 3. Feed system according to claim 1 or 2, wherein theintroduction system is provided with a heating device.
 4. Feed systemaccording to claim 1 or 2, wherein the introduction system is providedwith a heat exchanger and a flexible transfer line arranged outside thereaction chamber.
 5. Use of a feed system according to claim 1, inevaporators or in reaction chambers for chemical synthesis.